Human bio-potentials have long been measured in clinical settings for heath and/or performance monitoring purposes. For example, the heart rate (HR) of a human test subject may be monitored in a health clinic or other health care venue using an electrocardiograph (ECG) system. In a typical electrocardiography test, a plurality of ECG electrodes may be adhesively attached to the skin of the human test subject in order to record information pertaining to the heart. The measured bio-potential information indicative of the heart functions may typically be recorded on ECG graph paper or stored in computer memory for later analysis.
In general, conventional ECG electrodes may be formed of a conductive gel embedded in an adhesive pad onto which a cable is coupled. Examples include an adhesive conductive hydrogel formed over a conductive rigid sensor to which the cable is coupled or otherwise attached. ECG electrodes may be adhesively attached to different locations on the skin of the human test subject to obtain heart-related information from different angles (e.g., left arm, right arm, left leg, etc.). The electrical signals obtained by the ECG electrodes may then be interpreted by a knowledgeable expert to obtain certain information pertaining to the heart functions (e.g., heart rate (HR), heart rhythm, etc.) as well as to detect symptoms of pathological conditions (e.g., hypocalcaemia, coronary ischemia, hypokalemia, myocardial infarction, etc.), for example.
There are some disadvantages to conventional gel-based electrodes. Gel-based and/or adhesive-based electrodes may be unsuitable for long-term monitoring applications. For example, gel-based and/or adhesive-based electrodes tend to dry out over time and thus tend to be one-time-use-only devices. Furthermore, gel-based and/or adhesive-based electrodes, such as those employing Silver-Silver chloride (Ag/AgCl) electrodes, may cause skin irritation to some human subjects, especially if those electrodes are used over a long period of time. Moreover, the expertise and/or dexterity required to adhesively attach the gel-based and/or adhesive-based electrodes at various specific locations on the body often requires the use of an expert human assistant. The need for such expert involvement may be inconvenient and/or awkward for the user, and may drive up the cost associated with long-term monitoring.
The same issues may also render gel-based and/or adhesive-based electrodes unsuitable for use in the consumer market. For example, in addition to the aforementioned bio-compatibility issue, consumers may be resistant to purchasing, using, and discarding one-time-use gel-based and/or adhesive-based electrodes due to cost concerns and/or environmental impact concerns. As mentioned above, the attachment of gel-based and/or adhesive-based electrodes at specific locations on the skin may be intimidating and time-consuming to an average consumer and may require a level of expertise and/or dexterity that an unaided consumer typically may not possess.
Conventional dry electrodes have been proposed as an alternative electrode that addresses the aforementioned shortcomings of gel-based and/or adhesive-based electrodes. Such conventional electrodes may be based on metal filaments incorporated into thread and woven in different patterns. Skin compatibility and reusability may be greatly enhanced by using dry electrodes.
Conventional dry electrodes and associated amplifying circuitry have been incorporated into textiles (e.g., garments), resulting in textile-based monitoring clothing. See, for example, “Fabric-Based Active Electrode Design And Fabrication For Health Monitoring Clothing” by Carey R. Merrit and H. Troy Nagle (IEEE Transactions On Information Technology In Biomedicine, Vol. 13, No. 2, March 2009). Textile-based monitoring garments based on textile monitoring fabric have further been manufactured and made commercially available by different manufacturers.
One of the seismic shifts in consumer electronic trends in recent years has been the increase in processing (e.g., multiple core and/or faster processors) and communication capabilities (e.g., WiFi, Bluetooth, NFC, Cellular, 2G, 3G, 4G, and 5G) of smart personal communication devices (SPCDs) and the ubiquitous nature of the Internet in everyday life. More importantly, SPCDs have been widely adopted by consumers and are ubiquitous in the consumer market. For example, SPCDs incorporating both cellular telephony capability and computer-like data processing and communication capabilities have been widely adopted by consumers for communication, work, Internet browsing, health, personal fitness, and entertainment (e.g., movie watching, gaming, streaming media, social and professional networking, etc.). Examples of such SPCDs include smart phones and tablets incorporating operating systems such as iOS™ (available from Apple, Inc. of Cupertino, Calif.), Android™ (available from Google, Inc. of Mountain View, Calif.), Windows™ (available from Microsoft Corporation of Redmond, Wash.), and the like. Well-known contemporary brands of smart phones and tablets include, for example, iPhone™, iPad™, Samsung Galaxy™, Motorola Droid™, BlackBerry™, etc. These SPCDs are now ubiquitous and possess powerful communication and processing capabilities. The popularity and utility of SPCD's have resulted in them being carried by their users at all times or at least being kept nearby and ready for use.
The ubiquitous nature of the Internet, the pervasiveness of wireless communications networks, and the widespread adoption of SPCDs and their constant access and use by consumers has provided an opportunity to create comprehensive textile-based monitoring garment systems that may provide a level of capability and user-friendliness unavailable with the above mentioned conventional textile-based monitoring garment solutions.
Therefore, there is a need for improved electrodes, materials, ease of use, reduced costs and features in textile-based monitoring garment systems.
It is to be understood that, in the drawings, like reference numerals designate like structural elements. Also, it is understood that the drawings are not necessarily to scale.